Does the battery-icon show a black X and is loading in the other MacBook?
View attachment 921283
The battery-charging might be defective then. Ought to be a common problem in the early intel-MacBooks.
I had a black unit once showing that problem. Experience was as black as the book ...
Resold it marked as defective and I exactly described, what was wrong with that MacBook and that it could only be used as a desktop-machine, that it has to be always connected to the powerline to work. A lot of trouble with the buyer afterwards, who didn't read or believe my description ...